No matter who you are or where you live, everybody (and every body) reading this has two things in common: we’re mammals, meaning we belong to the class of animal that produces milk to feed their young – and we’re full of dangerous man-made chemicals known as per- and polyfluoroalkyl substances (PFAS).
PFAS chemicals are nasty. They don’t break down when they’re released into the environment, contaminating water supplies and soil, and they accumulate over time. They’re virtually omnipresent in modern society, and they likely cause a wide range of diseases, including thyroid disease, ulcerative colitis, testicular cancer, kidney cancer, and reproductive issues such as pregnancy outcomes and the timing of puberty.
Now, a study has shown another effect of these substances: an impaired ability to breastfeed. In an analysis following the pregnancies and births of more than 1,000 women in Denmark, researchers found that higher levels of PFAS chemicals in the blood made a new mother up to 20 percent more likely to stop breastfeeding early. The results are published in the Journal of Clinical Endocrinology and Metabolism.
“These man-made chemicals accumulate in our bodies and have detrimental effects on reproductive health,” explained lead author Clara Amalie Gade Timmermann. “Because breastfeeding is crucial to promote both child and maternal health, adverse PFAS effects on the ability to breastfeed may have long-term health consequences.”
To figure out the connection between PFAS chemicals and breastfeeding, the researchers first had to measure the levels of the chemicals in blood samples from the women. They concentrated on five major chemicals, including the pollutant perfluorooctanesulfonic acid (PFOS), the industrial surfactant perfluorooctanoic acid (PFOA), and the environmental contaminant perfluorononanoic acid (PFNA). If you’re wondering how you might have come into contact with such complex-sounding chemicals, you can find them in old-style Scotchgard, dental floss, and public drinking water supplies.
After delivery, the study participants provided updates about how breastfeeding was going in two ways: some sent their information to the research team via weekly texts, and the whole cohort was asked to complete questionnaires about their experiences at three and 18 months postpartum.
“Increased serum concentrations of PFOS, PFOA, PFNA and [all PFAS chemicals] were associated with a 16 percent ..., 14 percent ..., 14 percent ..., and 20 percent ..., respectively, increased risk of terminating breastfeeding at any given time after childbirth,” write the authors.
Over the past couple of decades, interest in breastfeeding has shot up as parents become more aware of the benefits to both mother and baby: "[b]reastfeeding decreases the possibility that your baby will get a variety of infectious diseases, ear infections, diarrhea, etc.,” according to the American Academy of Pediatrics, while mothers “return to their pre-pregnancy weight faster” and reduce their risk of various cancers. But even though the vast majority of US women try to breastfeed, many end up stopping early – whether they want to or not.
The reasons for that are complex, involving things like unsupportive work policies, lack of support from family or healthcare providers, mental or physical health issues, and more. So far, however, the idea that an otherwise healthy woman who wanted to breastfeed a child would be unable to is one that has largely been dismissed.
“Early unwanted weaning has been traditionally attributed to psychological factors, which are without a doubt important,” commented Timmermann. “[H]opefully our research will help shift the focus and highlight that not all mothers can breastfeed despite good intentions and support from family and healthcare professionals.”